Biopolymeric matrix implants have become important modalities for surgical and drug delivery applications, including but not limited to dura mater repair, burn therapy, wound care, guided tissue regeneration in orthopedic and dental surgeries, and controlled sustained drug delivery.
In a wound care application, a biopolymeric implant, e.g., a collagen membrane, can provide an active wound healing environment by supporting new tissue formation. Yet, an additional dressing is typically required to prevent or reduce bacterial invasion into the wound site. In the area of regenerative medicine and dentistry, biopolymeric matrix implants can be designed to provide appropriate mechanical properties, pore structures, and surface properties for either stimulating tissue ingrowth or preventing unwanted tissue growing into the implant in order to facilitate guided tissue regeneration.
The need exists for an implant having distinct density regions and capable of performing multiple roles after implantation. Such an implant should have the following properties: (i) a region of the implant is water or fluid-tight to prevent leakage of body fluid across the implant, (ii) the implant possesses regions of differential biomechanical properties, including tensile, tear, and peel strengths, (iii) the implant has a desirable degree of conformability, (iv) the implant facilitates cell ingrowth, is cell occlusive, or both, i.e., certain regions of the implant are cell occlusive and other areas are cell conductive, (v) the implant has certain in vivo resorption characteristics, namely, it has regions of differential resorption rates, and (vi) the implant can incorporate, in a particular region, bioactive molecules which can be controllably released in a sustained fashion.